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Related papers: La-substituted CaFeAsH superconductor with Tc = 47…

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We report the phase diagram for the superconducting system (${^{7}}$Li${_{1-x}}$Fe${_{x}}$OD)FeSe and contrast it with that of (Li${_{1-x}}$Fe${_{x}}$OH)FeSe both in single crystal and powder forms. Samples were prepared via hydrothermal…

We present a calorimetric study on single crystals of Ca(Fe1-xCox)2As2 (x = 0, 0.032, 0.051, 0.056, 0.063, and 0.146). The combined first order spin-density wave/structural transition occurs in the parent CaFe2As2 compound at 168 K and…

Superconductivity · Physics 2015-05-30 M. Abdel-Hafiez , L. Harnagea , S. Singh , U. Stockert , S. Wurmehl , R. Klingeler , A. U. B. Wolter , B. Buechner

We have grown single crystal samples of Co substituted CaFe2As2 using an FeAs flux and systematically studied the effects of annealing/quenching temperature on the physical properties of these samples. Whereas the as-grown samples (quenched…

Superconductivity · Physics 2015-06-04 S. Ran , S. L. Bud'ko , W. E. Straszheim , J. Soh , M. G. Kim , A. Kreyssig , A. I. Goldman , P. C. Canfield

The conductivity of the electron hole and polaron conductor La1-xSrxFe0.75Ni0.25O3-{\delta}, a potential cathode material for intermediate temperature solid oxide fuel cells, was studied for 0 <x < 1 and for temperatures 300 K <T < 1250 K.…

Strongly Correlated Electrons · Physics 2011-06-07 Selma Erat , Artur Braun , Alejandro Ovalle , Cinthia Piamonteze , Zhi Liu , Thomas Graule , Ludwig J. Gauckler

We report the experimental results of temperature dependent polarized As K-edge extended x-ray absorption fine structure (EXAFS) of LaFe1-xCoxAsO (x=0.0 and 0.11) single-crystals. By aligning the Fe-As bond direction in the direction of the…

In this paper we calculate the electron-phonon coupling of the newly-discovered superconductor LaO$_{1-x}$F$_x$FeAs from first-principles, using Density Functional Perturbation Theory. For pure LaOFeAs, the calculated electron-phonon…

Superconductivity · Physics 2008-07-08 L. Boeri , O. V. Dolgov , A. A. Golubov

We report pressure-induced superconductivity in a single crystal of CaFe2As2. At atmospheric pressure, this material is antiferromagnetic below 170 K but under an applied pressure of 0.69 GPa becomes superconducting, with a transition…

Superconductivity · Physics 2008-07-18 Tuson Park , Eunsung Park , Hanoh Lee , T. Klimczuk , E D Bauer , F Ronning , J D Thompson

We report the observation of a superconducting state below 8K coexistent with a spin-glass state caused by atomic disorder in Ce substituted Ca3Rh4Sn13. Measurements of specific heat, resistivity, and magnetism reveal the existence of…

Superconductivity · Physics 2016-06-16 A. Slebarski , J. Goraus , M. M. Maska , P. Witas , M. Fijalkowski , C. T. Wolowiec , Y. Fang , M. B. Maple

High pressure electrical resistance and x-ray diffraction measurements have been performed on ruthenium-doped Ba(Fe0.9Ru0.1)2As2, up to pressures of 32 GPa and down to temperatures of 10 K, using designer diamond anvils under…

Superconductivity · Physics 2014-04-15 Walter Uhoya , Georgiy M. Tsoi , Yogesh K. Vohra , Athena S. Sefat , Samuel T. Weir

Systematic measurements of the resistivity, heat capacity, susceptibility and Hall coefficient are presented for single crystal samples of the electron-doped superconductor Ba(Fe$_{1-x}$Co$_x$)$_2$As$_2$. These data delineate an $x-T$ phase…

Superconductivity · Physics 2009-05-02 Jiun-Haw Chu , James G. Analytis , Chris Kucharczyk , Ian R. Fisher

We attempted Ce doping in La2CuO4 with the K2NiF4 (T) structure by molecular beam epitaxy. At low growth temperature and with an appropriate substrate choice, we found that Ce can be incorporated into the K2NiF4 lattice up to x ~ 0.06,…

Superconductivity · Physics 2009-11-11 A. Tsukada , H. Yamamoto , M. Naito

The isostructural transition in the tetragonal phase, with sizable change in the anion-height, is realized in heavily H-doped LaFeAsO and (La,P) co-doped CaFe$_2$As$_2$. In these compounds, the superconductivity with higher-Tc (40~50 K) is…

Strongly Correlated Electrons · Physics 2014-05-08 Seiichiro Onari , Youichi Yamakawa , Hiroshi Kontani

A series of 122 phase BaFe$_{2-x}$Ni$_x$As$_2$ ($x$ = 0, 0.055, 0.096, 0.18, 0.23) single crystals were grown by self flux method and a dome-like Ni doping dependence of superconducting transition temperature is discovered. The transition…

Superconductivity · Physics 2009-02-27 L. J. Li , Q. B. Wang , Y. K. Luo , H. Chen , Q. Tao , Y. K. Li , X. Lin , M. He , Z. W. Zhu , G. H. Cao , Z. A. Xu

We have measured element-specific Fe-phonon densities of states (Fe-PDOS) of LaFeAsO_{1-x}F_{x} (x = 0, 0.11) and La_{1-x}Ca_{x}FePO (x = 0.13) by using nuclear resonant inelastic scattering of synchrotron radiation. The Fe-PDOS of…

Superconductivity · Physics 2008-12-25 S. Higashitaniguchi , M. Seto , S. Kitao , Y. Kobayashi , M. Saito , R. Masuda , T. Mitsui , Y. Yoda , Y. Kamihara , M. Hirano , H. Hosono

We observed a large decrease of Tc by no more than 3 at.% of Zn doped to the optimized superconductor LaFeAsO0.85 (Tc = 26 K), confirmed by measurements of electrical resistivity, magnetic susceptibility, specific heat, M\"ossbauer…

We report synthesis, structural details and magnetization of SmFe1-xCoxAsO with x ranging from 0.0 to 0.30. It is found that Co substitutes fully at Fe site in SmFeAsO in an iso-structural lattice with slightly compressed cell. The parent…

Measurements of the electrical resistivities, Hall coefficients, thermoelectric powers, electronic specific heat coefficients have been carried out for samples of LnFe1-yMyAsO1-xFx (Ln=La, Nd; M=Co, Mn; x=0.11) obtained by M atom dopings to…

Superconductivity · Physics 2015-05-13 Masatoshi Sato , Yoshiaki Kobayashi , San Chul Lee , Hidefumi Takahashi , Erika Satomi , Yoko Miura

A review of high-pressure studies on Fe-pnictide superconductors is given. The pressure effects on the magnetic and superconducting transitions are discussed for different classes of doped and undoped FeAs-compounds, ROFeAs (R = rare…

Superconductivity · Physics 2015-05-13 C. W. Chu , B. Lorenz

Synthesis of a series of layered iron arsenides Ca1-xRExFeAs2 (112) was attempted by heating at 1000 C under a high-pressure of 2 GPa. The 112 phase successfully forms with RE = La, Ce, Nd, Sm, Eu and Gd, while Tb, Dy and Ho substituted and…

CaFe$_2$As$_2$ has been found to be exceptionally sensitive to the application of hydrostatic pressure and superconductivity has been found to exist in a narrow pressure region that appears to be at the interface between two different phase…

Superconductivity · Physics 2009-11-13 Milton S. Torikachvili , Sergey L. Bud'ko , Ni Ni , Paul C. Canfield